Medical and surgical management of temporal bone fractures

History

In the conscious patient, hearing loss is often the most immediately reported symptom following head and temporal bone injury. Tinnitus may also be present and does not alter prognosis. Vestibular symptoms such as imbalance and dizziness often are exacerbated following ambulation. Symptoms of facial weakness, paralysis, and asymmetry suggest facial nerve injury, which warrant early surgical intervention. Determining the temporality and onset of facial symptoms is critical as this will help guide treatment planning. ^,

In the unconscious patient, eliciting a detailed history is not possible and therefore relies on obtaining information from individuals who may have arrived with the patient and may help characterize the mechanism of injury. The nature and etiology of TBF may help dictate the urgency of interventions; TBF from penetrating trauma due to gunshot wounds may cause neurologic and vascular injury requiring more immediate attention than TBF from blunt trauma, such as motor vehicle accidents.

Initial survey

Patients with suspected temporal bone trauma will be evaluated by the trauma team and assessed for life-threatening issues often before a complete temporal bone examination takes place. This consists of a full-body trauma assessment, including securing an airway, controlling hemorrhage and maintaining circulation, and examining neurologic status. The cervical spine should also be evaluated and stabilized.

Isolated TBFs are rare, which necessitates evaluation of the entire facial skeleton. Facial nerve function should be evaluated as soon as possible, particularly before muscle relaxants are administered, as this will affect examination accuracy and lose valuable prognostic information. An otologic exam should then be performed systematically, which focuses on the external and middle ear.

Otologic exam

The auricles and soft tissue are first inspected for exposed cartilage, hematomas, and lacerations. Hematomas should be incised and drained, and pressure bolsters are sutured to prevent “cauliflower ear” or auricular chondropathy. Lacerations are cleaned and closed. Retroauricular hematoma, also known as the “Battle sign,” may be present over the mastoid prominences, which is an arch-shaped bruising behind the auricle. This may point to a basilar skull fracture.

Next, the ear canal is inspected. Irrigation should not be used to remove cerumen or blood to avoid inadvertently introducing pathogens. The presence of brain herniation, fracture of the roof of the external auditory canal, middle ear effusions (e.g., hemotympanum), scutum fracture, and color of otorrhea should be noted. Otorrhea may be bloody or clear, which suggests a cerebrospinal fluid (CSF) leak.

The tympanic membrane should also be assessed for perforations. Typically, traumatic tympanic membrane perforations heal spontaneously, and no immediate intervention is needed. Pneumatic otoscopy should be used judiciously and not be used in the early period following injury as this may introduce air or bacteria into the intracranial space or inner ear via a CSF fistula or otic capsule disrupting fracture.

An operating microscope may be used following stabilization to further evaluate the ear canal, tympanic membrane, or middle ear and may be required to remove a foreign body, if present. Packing of the ear canal is not generally initially needed unless significant hemorrhage is present. If profuse hemorrhage is present, management via balloon occlusion or carotid ligation may be used.

Hearing assessment

An early bedside evaluation with a 512-Hertz tuning fork allows for documenting baseline hearing function and potential hearing loss. The Weber test is performed by placing the base of a struck tuning fork on the forehead, nose, or teeth. The patient is then asked if the sound is louder on either side. Typically, a patient with unilateral sensorineural hearing loss (SNHL) will lateralize sound toward the unaffected side, whereas a patient with unilateral conductive hearing loss (CHL) will lateralize sound toward the affected side. There is no sound lateralization in a normal test.

The Rinne test is a follow-up test performed for each side by placing the base of a struck tuning fork on the mastoid and then held near the meatus. The patient is then asked if the tuning fork is louder near the meatus (evaluating air conduction) or when applied to the mastoid (evaluating bone conduction). A patient with a moderate CHL will report louder bone conduction than air conduction on the affected side. A patient with normal hearing will report louder air conduction than bone conduction (i.e., considered to be a positive Rinne) but does not exclude sensorineural hearing loss in the tested ear.

Combined results from the Weber and Rinne tests will help characterize the underlying nature of hearing loss. A patient may have CHL if the Weber test lateralizes to the affected ear and a negative Rinne is present. Patients with SNHL may have variable tuning fork findings. A Weber test that is louder on the affected side suggests SNHL and the Rinne test will generally be positive, unless if there is significant hearing loss. Audiograms are generally not obtained until the patient's condition is stabilized, unless if urgent complications such as CSF leak or facial paralysis are noted, which guides treatment approach in cases with residual hearing.